Altered gene expression in the spleen of adolescent rats following high ethanol concentration binge drinking

Binge drinking of alcoholic beverages among adolescents is a common practice that can have serious health consequences. Alcohol is a potent immunomodulator that alters a wide range of immune responses. However, it is unclear whether there is a differential immune response to alcoholic beverages with a high versus low concentration of ethanol. In this study, we used a PCR array containing 46 primer pairs of selected genes to compare mRNA expression in the spleen, an immune system organ, of adolescent rats following binge drinking of alcohol solutions containing either 20% or 52% ethanol (v/v, 4.8 g/kg daily dosage), or water (control) for 3 d. We found that, expression of IL-1β, IL-6, CCL2, and GABA(A) receptor α2 subunit in the spleen were decreased, and mGluR5 and 5-HT3A receptor expression were increased after administration of an ethanol solution containing 52% ethanol, but not one with 20% ethanol. Our data suggest that alcohol-mediated immunomodulatory effects are, in part, dependent on the ethanol by volume concentration. This is the first study to show that exposure to a high ethanol percentage beverage can have more profound effects on immune responses than one with a low percentage of ethanol.